Mass Mail Christmas Email Template + supported in Odoo v10, v11, v12
Find duplicate emails and delete in the mailing list
Use the QWeb templating mechanism for emails
Know and track (un)subscription reasons, GDPR compliant
Copy tracking fields from leads to partners
Enforces 1 registration per partner and event
Disable mass mailing to partners by default (opt-out)
Avoids duplicate mailing lists and contacts
Show additional social icons in Mass Mailing snippet